Oil leaks

Maintained by mods and admins. but contains all the answers to all those questions that get asked over and over and over . .
Locked
User avatar
knackeredMk1
Super Moderator
Super Moderator
Reactions:
Posts: 4182
Joined: 03 Nov 2006, 17:41
Bike Owned: Modified Mk1
Oil leaks

Post by knackeredMk1 » 05 Aug 2014, 10:58

Two stroke oil leaks -

Most probably from the oil level sensor. The oil seeps out around the sensor and runs down the frame/reservoir to collect on the bottom rails before dripping on the floor. To stop this leak you need to drain down the oil to below the sensor and then thoroughly clean the sensor and the surrounding reservoir with contact cleaner. Then apply a good silicone sealant to the sensor before refitting it. Leaks can also be caused by leaking hoses or connections.

Worst of all it could be the seal between the oil pump and the crank case leaking, allowing oil to flow into the crank case and out of the crank breather tube. This is much less likely though.

Gearbox leaks -

Usually a worn seal. Can be found by cleaning the engine and looking for oil trails. Can also be cracked casing or leaking gaskets.

Oil out of the gearbox breather tube -

Often overfilling of oil in the gearbox. Otherwise can be either crank seals leaking pressure from the cylinder or the seal between the oil pump and the crank case going so two stroke oil leaks into the crank case.

User avatar
knackeredMk1
Super Moderator
Super Moderator
Reactions:
Posts: 4182
Joined: 03 Nov 2006, 17:41
Bike Owned: Modified Mk1
Replacing crank case drive shaft seal

Post by knackeredMk1 » 01 Oct 2014, 14:35

Empty the oil out of the gearbox and clean (wire brush) the and of the drive shaft where the sprocket sits.

To get the seal out insert one or two self tapping screws into the middle of the seal until they have enough purchase for you to pull the seal out by pulling the screw(s). You can remove seals with a screwdriver or a braddle - just make sure you don't scratch the casing where the seal fits in.

Stretch some insulation tape over the spline shaft where the sprocket sits.

Lightly oil the output shaft. Gently slide the seal over the end of the shaft and work it down until it sits in place. You might have to tap it home using a piece of wooden doweling. Work it gently from different positions don't get it sitting home on one side whilst the other side is millimetres out.


Locked